Convertible structure for buildings or the like



Jan. 19, 1943. H. L. MARTlNus CONVERTIBLE STRUCTURE FOR BUILDINGS OR THELIKE Filed July 16, 1942' 3Sheets-Sheet 1 3 sheets-sheet 2 HUH@ Jan. 19,1943. H. 1 MARTINUS CONVERTIBLE STRUCTURE FOR BUILDINGS OR THE VLIKEFiled July 16, 1942 @Hans L. frZzL/zws I Jan. 19, 1943.

H. L. MARTINUS CONVERTIBLE STRUCTURE FOR BUILDINGS OR THB LIKE FiledJuly 16, 1942 3 Sheets-Sheet 3 NUN {Iwo/26% mm vm Patented Jan. 19, 1943ACONVERTIBLEl STRUCTURE FOR BUILDINGS R THE LIKE Hans L. Martinus,Chicago, Ill., assignor to Gun.- nar Mortensen, Chicago, 111.

Application July 16, 1942, Serial No. 451,197

(Cl. 2li-2) 8 Claims.

This invention is directed to novel constructions and combinations ofstructural features utilizable in the construction of units such asbuildings, barges and other shelter units adapted particularly forrelatively quick and inexpensive construction and adaptable for use forstorage, shelter and other uses hereinafter recited.

Recent developments, particularly in the field of relatively temporaryconstruction in numerous instances required in connection with variousmilitary and civil uses, have presented a definite need for portableunits adapted for storage and for relatively easy transport from onelocation to another, wherein in addition to the requirements ofportability and quick and inexpensive construction, there is thedefinite need for a ventilatable shelter under varying conditions ofweather and atmosphere, and which at the same -time will require a veryminimum amount of material so that the problem of transport of thematerial is comparatively easy and inexpensive.

For example; in the establishment of military bases, both temporary andpermanent, an lindispensable requirement is the ability to quickly buildportable units for storage of equipment and other uses with the leastamount of materials from the standpoints of both volume and weight ofthe materials.

It is an object of my invention to provide composite and convertiblestructures for buildings and other material-containing units wherein askeleton or frame structure, preferably made of wood, maybesatisfactorily covered by a plurality of pre-fabricated and pre-formedcomposite sheets or strips, which themselves may be made up in rollformand relatively easily transported to ,the situs of the unit to beconstructed, and which strips are reinforced, by an intermediate metalfabric which imparts strength, stiffness, rigidity and a means forsecurely nailing such strips into overlapped, overlying `and superposedpositions upon either side walls, roof or other parts of a building ormaterial-containing unit.

A further object of my invention is the provision of a building unitwherein one or more walls thereof are formed by a series ofedgeoverlapping longitudinal composite strips which included a bonded-inmetal fabric and wherein each portion of the strips are formed solely ofcontinued portions of the said metal fabric so as to provide vents orports for the buildings in instances where passage of air into and outof the building is a requirement.

A further object of my invention is the provision of composite wallconstructions which include truss mounting means and aplurality ofweather-proof strips which are bent in a downwardly and outwardlyinclined position and wherein the lower edge portions. of one or more ofthe strips forming the Weather-proof wall are doubled back inwardly,upwardly and toward the framework of the building to provide both meanswhereby the strips are secured to the framework as well as providing airvents into which rain or the like cannot normally enter.

A further object of my invention is the provision of the aforesaid metalfabric-contained strips in wall constructions wherein a portion of thebonded-in fabric of the strip is itself extended beyond themoisture-proof parts thereof, and bent angularly into positions toextend toward and adjacent to the building framework so that the stripscan be thereby additionally secured by nailing through the metal fabricinto the framework to thereby provide optional vents,A

and of providing closure strips selectively adapted to close the ventsthereby formed.

A further object of my invention is the provision of compositeconstructions of portable units including framework of wood or the likeand a plurality of edge-overlappingand secured layers or strips ofwater-proof material, preferably composed of bonded-together felt andwire fabric layers, and wherein the strips of water-proof material .arenailed along their lateral edges as well as intermediate points to theframework and thence doubled back and extended along the framework tocover areas beyond the points of original securance substantially ashereinafter described, said units being capable of use as water vessels,barges orr the like.

Other and further important objects of my invention will be apparentfrom the following specification and claims.

This invention, in a preferred form, is illustrated in the accompanyingdrawings, reference being made thereto in the following description.

On the drawings:

Fig. 1 is a reduced perspective view, with parts broken away, of oneofthe wall sections, layers or strips, adapted to form a part of a wallof a building or equivalent unit.

Fig. 2 is a vertical cross sectional view, with parts broken away, ofone wall or adjacent portion of a typical building utilizing myinvention, and including a partial cross section of the floor andfoundation thereof.

fface.

perpendicular wall portions utilizing my inven-A tion.

Fig. 6 is a cross sectional view taken on a vertical plane through aside wall, and a part l of the roof end and foundation structureillustrating the use of my invention.

Fig. 7 isa side elevational view of the side wall portion adjacent acorner of a so-called portable unit utilizing features' of my invention.

Fig. 8 is a cross sectional view taken on line 8 8 of Fig. '7. i iReferring to Figs. 2, 5 and 6, reference numeral 2,sos,7ee

framework, may be mounted and secured in the conventional manner with.the ends of the joists optionally, though not necessarily, resting'uponthe extended metal fabric edge areas I3 as illustrated in Figs. 2 and 6.

I have illustrated only a small part of the structure embodving featuresof my invention, in which illustrations .but a few of the verticaljoists or beams I4 are illustrated, it being understood that` ments ofthe particular case., One vertical corner l designates a suitablefoundation, which may be of any conventional form, and which may beeither partially extending above normal surrounding ground surface or incases of temporary buildings, may be merely laid upon a level groundsurfoundation is formed of suitably connected horizontally extendingbeams, which may be nailed or otherwise fastened together at theirrespective junctures. It will be noted at the lower left of Figs. 2, and6, that the longitudinal founda.

illustrationis composed' of a plurality of side byy side boards whichare illustrated in cross section. In Fig. 5, the floor boards of saidfloor II are not nailed directly up on'the transverse floor joists,

but upon the upper surface of an interposed layer I2 of waterproofmaterial of the type hereinafter described, namely a plurality ofbonded-together felt and fibrous layers with an optional intermediatedbonded wire fabric as illustrated. In

In the particular illustration shown, suchA the'illustrations of Figs. 2and 6, said floor layer I2 of waterproof sheeting, (composed ofedgebonded, coated felt or fibrous strips) is laid and secured upon thesurface of the floor Ii over its entire area. In the said figures, itwill be noted that the edge areas, that is either the longitudinal edgesor the end edges of the strips laid upon the floor, are composed solelyof wire fabric, thlsbeing accomplished by either extending the bondedwire fabric of the composite strips beyond the edges of the felt stripsof the said floor composite layer,

or by stripping off the felt layers along the edges` so as tosubstantially expose only the wire fabric. Said extended andsubstantially horizontally exposed edge areas of wire fabric I3 forminga continuation of the metal fabric of the floor layer i2 are preferablylaid completely to the edges of the floor, before the vertical joists ofthe building frame-work are mounted, and such extended metal fabric edgeareas I3 are preferably, though not necessarily, bent upwardly asindicated in Figs. 2, 5 and 6, where they will be secured by subsequentnailing of the lowermost side wall composite strip hereinafterdescribed.

After said composite iloor layer I2 and its integral extended metalfabric edge areas I3 are laid upon the floor as described, the verticalbeams or joists I4, which form a part of the skeleton joist Ilka isillustrated in Fig. 3 and will be referred to hereinafter.

The vertical beams orjoists I4 are securedto gether at their upper endsin any well known` manner, as for example by horizontally extendingtrusses I5, a fragment of one of which is illustrated in Figs. 2 and 6.The support for the roof may be formed in 4any conventional manner, onepreferred form being illustrated in Figs. 2 and 6, in which a part of aninclined roof truss Itis illustrated as secured by nailing or the likeatits lower end to theupper end of the correspondingly spaced verticallyextending side wall-supporting joists Il. As distinguished from aconventional building frame orskeletn, the inclined roof supporting,truss I6 terminates iiush with the outer side surface of theside wallvertical trusses and'` of my invention, there need be no horizontallyextending braces or trusses between the hoor and' the upperhorizontalltrusses I5, this being one feature of economy attainable inutilization of my invention. v

In the framework shown at thelower left hand portions of Figs. 2, 3, 5and 6, the lowermost part of the side of the building, `(including thesidesurface of the floor or foundation)` has secured thereto alongitudinally extending strip I'I of waterproofmaterial which hasbonded thereto or theref i into a reinforcing andstrengthening metalfabric I'Ib which is preferably composed of woven wire havinginterstices of suilicient size to permit a hot plastic composition torun therethrough.

The term strip is used to designate `the first and lowermost row ofindividual pieces of composite waterproof material, whichpieces may besecured intoend over end overlapping relation at the juncture of onepiece with the other so that said strip I1 extends preferably, thoughnot necessarily, completely around the building and a relatively shortdistance upwardly from e the ground surface. l This strip Il keeps themoisture from the ground while, being absorbed bythe major part of theoor or foundation and prevents rain or the like from contacting thefloor or foundation portions and the lowermost parts of the verticaljoists. l

As shown in the drawings, the lowermost strips I1 are preferably nailedon at suitable spaced apart points so that the nails pass into eithersome part of the floor or foundation or into the lower aaosgcc Where itis desirable to securely anchor :ip l'ieA building against wind brotherelements where ri-.se are likely tobe `encountered in particularlocalities, lit is advisable to utilize vra relatively, wider strip I'Ihaving a substantiall portionof felt layer removed and entirely omittedso as'to `provide a metal fabric anchor portion IIa shown at of Fig. 5,'and Vwhich desirablymay be bent outwardly Vand downwardly'and buried inthe lower left the surrounding earth, so that said metalj fabric portionIlaprovidesan formed *anchoring element for the 'building'. Referring tothe form of theconstruction'illusf' trated in Figs. l compositewaterproof and weatherproof i material are formed, preferably in rollform `for con-'- venient transport, and which 'strips of material ,20

are preferably composed of two or morela'yers'of 'r felt or otherequivalent"fibrous"l material similar to that commonly referred'` 'tolu'as' roofing paper,`

bonded between two or more layers of vfeltfor` other fibrous material orbondedor pressed into' one flat surfacethereof. In the particularillustration of .the drawings, thewoven wireffabri'c designated bynumeral"I8,"^2, ispshown as` bonded between the felt layers, the sameincluding suitable bonding composition applied as a plastic to bond therespectivelayers of fabricinto one composite substantially flexibleunit.'l In the manufacture of these composite sheets at the time ofproduction, such partsthereo'f whichy are to be utilized for temporaryventilated buildings, have the woven metal fabric ,of greater area sothat one longitudinal edge of 'saidmetal fabric ex,- tends several'inches beyond'ther'nain:weather-Y proof portion of the compositestripsQthis'provid-` ing an integral longitudinal edge -formed solely ofmetal fabric and designatedv by reference numeralI9. l

As this composite covering vmaterial is preferably brought to thelocation vof'actu'al use in flat sheets or in rolls capable of beingrolled out flat, those strips in connection with which air vents of thelengths desired are cut oi,`and eachstrip of composite material 20 isbent alongl a' longitudinal line preferably a short distance inwardlyYof the edges of the felt material 'adjacent to the metal fabric edgeportions I9 to form afdoubled back part or flange`2l composedprincipally of apertured metal. The exposed metal. fabric edge portionI9 is then' bent angula'rlyl and preferably, though not necessarily, ina substantially vertical direction to the plane of the main body ofthecomposite covering strips 20, 'and the outer edge of the flange 2I ispreferably again bent upwardly or downwardly to present aflange-likeportion for convenient nailing to thevertical joists of the framework.Said first mentioned bend of said vent-forming flange is designated forconvenient reference as numeral 22, and the longitudinal bend whichforms a convenient nailing flange or innermost edge portion isdesignated by reference numeral 23. The doubled back vend portion formedby the longitudinal fold or bend made inwardly of the exposed metalfabric portion I9 inexpensive eand quickly..

1 and 2, a pluralityof strips of 3.0. against and thefsame xransvdrivenfthroughiboth thirebrmrms e secured'to thefr'amework by nailing or`equivalent means, thenailszbingdriven throughthe integrallarigtudieallrs metal f abric pending'ilan :is lf'ullyformed Asothat thebuilders may 5swingV theirllianimers' without-interference' and whilethe mainv bodyiofth'ecoveringstrips' "areextended' in a direction'awayfrom the building framework fitself. After said nailsfare-y driveA@through `said metal fabric flange, the `main f Abod of eachstrip islifted upwardly tov complete" the 'end'fo'rming the depending flange! Ifof each row 'f'strips, aridE thereupon the uppermost longitud ledge'ofeach'cveringfstrip 20 is'I secured to'the vertical' -fljoistsfoffthe building `framework 1 eitherfby vsep'arate'nailing"or-l by theInails 4which are driven" eithrl'ithroug'h' the bent backl loweredgefnailing'flange 23-offthe-next adjacent covering istrip 20, y'or 1through 'the' vlower substantially flatedge portionfofitheadjacentstrip. f w

A s illustrated at the left hand portion of Fig. 2, when? the upperlongitudinal edges `of Vv.one f row of covering strips' f2 I), vare*place'dfagainst the side wall joiststhefupwardly bent nailing anges-23ofthe metalffabric'exposed area* I9 is `placed therelarlybentimetal-fabricedge areas I9 holdsthe Y lowerdoubledibaclsi flanges 2Ioffeach strip la short distance away from the buildingframework,l andholds`= the lmain bodyfoff the weatherproof cover-v ing strips 20"'n-aslightly inclined position, and thereby forms r i downwardly1 opening.air vvents which extendftol the length, that said aforedescribedconstruction is adhered .to. Such longitudinally extending air vents,designated generally-as 24, maybe formed either entirely arounda'building at spaced apart intervals, or at either the -juncture of vtwoadjacent strips or at'the spaced apart junctures of two or moreof thecovering strips` lall according to the-desired `ven-- tilationof theparticular building. It will be aD- parent that the'lengths, sizes and`number of such longitudinally extending l downwardly '1. openingvent-openings," which are `obstructedsolely by the interwoven wire whichreadily admits air, can be regulatedaccording to `theidesires of theparticulaxvcase` to meet Ithe particular krequirements of theintendedusesofthe building, and itfwillbe further apparent that i such.longitudinally extendinggventsgwill .be guarded against normal Weatherconditions by the downwardly extended overhanging flanges formed by thesaid doubled back edge portions of the covering strips.

As indicated in Figs. 5 and 6, the composite sheets which include areinforced metal fabric as a part thereof which are secured to the sidef depending flange which acts as Y -va'fguardag'ainst rain or'the'relementsasfsub- St'antially shown cross section inlfigs. l2,15

xten'dingnailing flange 23 of -sa'id screws or the like.

in mounting to the end strips 20a which are illustrated in part in theright hand Darts oi."

Figs. 5 and 6.

As illustrated in Figs. 2 and 5, the longitudinal air vents 24 formed ashereinbefore described, may be substantially closed against any materialpassage of air therethrough by means off longitudinally extendingboards, strips or bames 25, which are illustrated in upstanding positionupon their respective edges, and when`it1fi'sdesired to substantiallyclose said vents to restrict the amount of ventilation, wind, etc.,these balles limited to any particular type or construction ofweatherproof roof covering.

In Figs. 1 and 6, I have illustrated in cross section fragments of anoptional form ofv roof Iin which the longitudinally extending strips areformed of a fibrous or other suitable material having bonded thereinto areinforcing metal fab# ric of the type hereinbefore described,andwherein the roof strips, designated as 28, are nailed along the onelower edge by being first placed downside up, the nails driven throughthe, overl. lapping lower edge of said inverted strip through 25 may be1aid flat in ahorizontal plane 'resting upon the horizontally extending'portionsbf the tending metal fabric portions also guard against theyentry of insects.

I desire it to be understood thatthe number to desire and any one ormore thereof may be positioned at the desired height from the groundatthe points ofjuncture of any two rows of acljacent wall coveringstrips. It will be apparent that side wall covering strips having ventsformed like those hereindescribed, may vary in direction in differentbuildings, as for example all of the side wall covering strips could besecured as above stated in edge-overlapped inclined or ver-V ticaldirections and at the saine time being provided with portions ol.' oneor more of the wall covering strips bent inwardly and apertured andsecured to the side wall frame supports to provide the desired number ofair vents opening in directions other than downwardly In Fig. 3 I haveillustrated a lower portion of a typical corner of a building utilizingmy hereindescribcd constructions wherein the end wall covering of thebuilding shown at the right oi' Fig. 3 is' composed of edge-overlapped'composite strips 2il`which are preferably secured by nails to thevertical wall supports of the frame substantially as illustrated. Itwill be seen that the upper edge of the next adjacent strip therebelowand into the roof supporting members of theV building frame. Thereuponthe inverted strips or sheets of said material are bent completely overto double the edge portions adjacent to the nailed parts and then thesame cycle of overlapping and doubled back securance may be Arepeatedwith respect to the next and upper strip 28 of the roof covering. Anenlarged fraginentary view of the manner in which the roof coveringstrips 28 are secured upon the rooi l"trusses i6 and doubled back to layupon the roof E fof' air vents formed substantially in the manner i'hereinbefore described may be varied according supports of the frame isillustrated in the enlarged fragment of Fig. 4.

In Fig. 6 I have illustrated in vertical cross section a side wallembodying one of the features of my invention, and wherein `each of therespecthese end wall strips 20 extend l short distance beyond the cornerjoists Illa and haveV the extreme edge portion designated as 28 bentangularly upon and over the end edge portion of the side wall strips 20shown at the left of Fig. 3. In this view, both the two side wall strips20 at the left of Fig. 3 are illustrated as being in slightly downwardlyinclined position in the same manner as shown in cross section in Fig.2. The end portion 26 of the two end wall strips 2li which forni scalingliangcs and a weatherproof joint with the ends respectively of the sidewall strips 20, may be secured to said side wall strips in any suitablemanner, as for example by suitable cement, plastic composition, sheetmetal In Fig. 3 the particular optional form of said securing means isrepre-l sented by sheet metal screws 21.

ln the drawings I have illustrated an optional form of roof covering,though I desire it to be understood that any satisfactory form of aconstruction of roof may be utilized in connection with my invention, myinvention being in no way tive longitudinally extending covering stripsoi' the side wall are secured so that the lower longitudinal edge isdoubled back upon .itself and "securing nails passed through the edgeflange 'and through the underlying upper edge of the next adjacentcovering strip and into the side wall supports of the building frame.This is most economically accomplished in the building operation bylaying the strip inside out with the upper edge thereof flush with theupper edge of the already secured strip, driving the nails at spacedapart intervals through both the said overlying edges and intdthe sidewall members of the frame, and thereafter taking each strip'or row ofstrips and folding it outwardly and upwardly letting its upper edgeportions lie against theV side wall supporting members, whereupon theoperation is again repeated with respect to the next adjacent coveringstrip.

A portable unit made according to the hereindescribed invention providesnot only a weatherproof and substantially durable shelter, whichoptionally includes the air vents as hereindescribed, but also providesastructure and a roei?YAY and wall covering having a high degree of.resistance to fire, and being to a substantial degree shatter proof sothat fragments of bombs, shells and other explosives which might explodein close proximity will not penetrate the side Wall and roof structuredue to its resiliency or flexibility nor result in any substantialbreaking away or flying of splinters such as encountered in ordinarywood walls and coverings.

In Figs. 7 and 8, I have illustrated the `portable unit capable of useeither as a building or shelter or as a barge or boat which embodiesfeatures of construction which have been heretofore described.

In this illustration, a different style or form of frame structure iillustrated, and such frame may bepvaried according to the particulardesire and requirements of the job. In the particular illustration,reference numeral 29 designates a base beam which extends longitudinallyfrom end .to end of the structure, and numerals 30 designate'typicaltransversely extending joists disposed in subon, the side wall beamsbeing stantially vertically extending directions; a side wall coveringon said side walled beams composed of a plurality of superposed rows ofcomposite weatherproof composition and partially of a bonded Woven Wirefabric; the wire fabric unit of each of said strips itself extendingbeyond.

one lateral edge of each of said strips; the lower portions of certainsaid strips being bent inwardly and the extending metal fabric portionsalong said bent in edge being bent horizontally and extending topositions adjacent the side wall beams of said framework; fasteningelements securing the lateral edge portions of said wire fabricextending portions to said side walled beams; said inwardly extendingmetal fabric portions providing downwardly opening air vents for saidbuilding; and a plurality of edge-overlapped strips of waterproofmaterial forming the roof portion of said unit.

4. In a portable building unit; a supporting framework including sidewall and roof supporting members; and substantially shatter-proof wallssecured on the side wall members of the said supporting frame, said sidewalls being composed of a plurality of edge-overlapped slightlyyieldable strips formed of sheets of fibrous material and metalreinforcing fabric edge bonded together as integral units, certain fsaid composite strips having their longitudinal edges doubled back uponthe main portions thereof and said doubled back portions secured inoverlapping relation with respect to the longitudinal edge portion ofthe adjacent composite strip, one or more of said side walls having airvents therethrough `provided by angularly bent aperturebearing portionsof one or more of said strips of material covering said side wall.

5. In a quickly assemblable and portable building; a supportingframework including vertically extending side wall members and roofsupporting members; a weather-proof covering secured on said roofcomposed of a plurality of edge-overlapped strips of waterproof materialsealed at the respective joints of said strips, said strips ofwaterproof material being composed of a fibrous flexible material and areinforcing metal fabric bonded thereto; and a plurality oflongitudinally extending exible strips composed of fibrous material andreinforced metal fabric bonded thereto secured on said side walls insubstantially edgeoverlapped relation and forming weatherproof sidewalls for said building, one or more of said longitudinally extendingstrips having the metal fabric thereof extended and exposed along thelongitudinal edge of such covering strip, and said exposed metal fabricstrip edge portion being bent angularly and inwardly and secured to theside wall members of said frame so as to normally hold such strip inslightly inclined position and to thereby form longitudinally extendingair vents for said building.

6. nia quickly asse blabie and portable building; a. supportingframework including extending side wall members and a plurality ofspaced apart inclined roof supporting members; a weatherproof coveringsecured on "saidroof composed of a plurality of edge-overlapped stripsof we.- terproof material sealed at the respective joints of said'strips, said strips of waterproof material being composed of a brousflexible material and a reinforcing metal fabric bonded thereon; aplurality of longitudinally extending ilexible strips composed offibrous material and reinbonded thereto secured on forced metal fabricstrip extends substantially beyond said side walls in substantiallyedge-overlapped relation and forming weatherproof side walls for saidbuilding, one or more of said longitudinally extending strips having themetal fabric thereof extended and exposed along the longitudinal edge ofsuch covering strip, and said exposed metal fabric strip edge portionbeing bent angularly and inwardly and secured to the side Wall membersof said frame so as to normally hold such strip in slightly inclinedposition and to thereby form longitudinally extending air vents for saidbuilding; and a longitudinal strip extending about the lowermost part ofsaid frame and composed of strips of material with end edges overlappedand which strips are composed of Woven metal fabric partially covered byweatherproof material so that the lower part of said strips are composedsolely of said Woven metal fabric and are adapted to be bent angularlyand buried in the surrounding earth to provide anchoring means for saidbuilding.

'7. In a portable structure having a framework including inclined rooftrusses; side wall supporting joists, bottom beams and braces, all saidframework members being connected together to define a pliable space;v abottom composed of a plurality of side by side Wood boards secured tothe bottom members of said framework; longitudinally extending side wallmembers connecting the vertically extending side Wall members of saidframe; a waterproof covering secured upon the bottom on the side walland end wall portions of said structure comprising a plurality oflongitudinally extending strips of composite waterproof materialincluding a metal fabric bonded therein; one lateral edge of each ofsaid strips being secured by nailing or the like to said bottom boardsand the remainder of each strips being doubled back`and folded adjacentto and secured to said bottom boards; each next succeeding strip havingone longitudinal edge portion secured by nailing or the like to thedoubled back portion of the preceding strip, the main portion of suchstrip being doubled back against said framework and secured thereto, andeach succeeding strip being similarly secured and doubled back; thelongitudinally extending overlapping edges of said strips being sealedto form a continuous composite waterproof bottom end Wall.

8. In combination enclosed structure of the type described, saidstructure having a rigid framework defining an interior space andincluding a plurality of supported longitudinally extending wood Sidestrips and a braced floor including a plurality of secured side by sideboards; said structure having waterproof end walls at the opposite endwalls thereof; a waterproof composite wall covering the undersurface ofsaid oor and covering the sides of said structure composed of aplurality of metal-reinforced wate'proof flexible strips of compositematerial, the central bottom strip extending longltudinally andcontinuous from one end to the other of said structure; each of the twostrips adjacent said central strip forming a portion of the covering ofsaid bottom and said side walls being folded and doubled back along alongitudinal line so that one edge area is positioned and secured bynails or the like to one lateral edge portion of said centrall bottomstrip and so that a larger doubled back portion of each of said twostrips adjacent said central the lateral edgesrespectlvely of saidcentral strip; each of with a portable, habitable the succeedinglongitudinally extending Wamelproof composite strips having onelongitudinally e extending edge portion secured by nails or the liketothe extended portion of the adjacent preceding strip and being doubledback along a longitudinal line and the larger doubled back portionpositioned and secured against the bottom and side wall of saidstructure respectively so as' to form triple layers of said stripmaterial over on portions thereof between the points of securance andbetween the respective longitudinally extending folds of said respectivestrips,t said triple layer wall thereby formed forming a Waterproofsubstantially rigid covering for the bottom of the side walls of saidstructure.

HANS L. MARTINUS.

